44 lines
2.1 KiB
NASM
44 lines
2.1 KiB
NASM
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;=----------------------------------------------------------------------------=;
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; GNU GPL OS/K ;
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; ;
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; Desc: Basic Memory Long mode Functions ;
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; (x86_64 architecture only) ;
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; ;
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; ;
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; Copyright © 2018-2019 The OS/K Team ;
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; ;
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; This file is part of OS/K. ;
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; ;
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; OS/K is free software: you can redistribute it and/or modify ;
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; it under the terms of the GNU General Public License as published by ;
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; the Free Software Foundation, either version 3 of the License, or ;
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; (at your option) any later version. ;
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; ;
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; OS/K is distributed in the hope that it will be useful, ;
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; but WITHOUT ANY WARRANTY; without even the implied warranty of ;
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; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;
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; GNU General Public License for more details. ;
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; ;
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; You should have received a copy of the GNU General Public License ;
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; along with OS/K. If not, see <https://www.gnu.org/licenses/>. ;
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;=----------------------------------------------------------------------------=;
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[BITS 64]
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;; GLOBAL DATA
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A20_OK db 0
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;; TEXT
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check_a20:
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cmp BYTE [A20_OK], 1
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je .A20Success
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mov bl, 0x0C
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mov esi, Fail
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call write
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jmp Die
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.A20Success:
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mov bl, 0x0A
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mov esi, Pass
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call write
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ret
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